Releasable locking mechanisms for machine parts are not broadly new per se. For example, German Patent DE 3,346,661 shows an assembly wherein the spring ring can be inserted into radial grooves in the bore and lateral surface of machine parts wherein both the surfaces of the bore and its outside surface are cylindrical. The ring thus can be used to lock the machine parts in the axial direction and can also be used to lock a shaft in a bore. It is noted that in this type of application, the radial grooves are made deep enough to hold the entire radial dimension of the spring ring. In this type of application, the radial grooves are made deep enough to receive the entire radial dimension so that the spring ring is completed seated within the groove. In other words, the depth of the groove is greater than the radial dimension of the spring ring. Accordingly, as the shaft is first inserted into the bore, the spring ring is pushed into one radial groove and upon completion of the assembly process, and it then snaps into the other radial groove in the shaft. Accordingly, since the spring ring is no longer accessible from the outside, the arrangement described above is considered a permanent installation.